Fuel pump apparatus



Sept. 29, 1964 J. s. BERNARD ,5

FUEL PUMP APPARATUS Filed April 17, 1962 i i M l 1 /////////////W////////////////{/V m N O N INVENTQR.

United States Patent 3,150,595 FUEL PUMP APPARATUS John Springer Bernard, 2060 East 4800 South St., Salt Lake City, Utah Filed Apr. 17, 1962, Ser. No. 188,082 2 Claims. (Cl. 103-37) This invention relates to internal combustion engines. Its primary objective is to provide an improved and useful apparatus with which to meter and pump specific amounts of liquid fuels. The apparatus may also serve to pump liquids other than fuel when the delivery of metered amounts of such liquids are desired.

The novelty in this invention is in the manner of metering amounts of fuel and in the manner of alternatively increasing or decreasing the effective stroke of the apparatus piston. Prior to these concepts, helical valves and a various assortment of threaded racks have been employed for these purposes. This invention employs a floating shaft technique.

This invention is not concerned with the particular tube and/or valve structure used for the final delivery of the fuel. It only provides the means for metering and pumping the specific amount of fuel to be so delivered. The principles involved in this metering and pumping operation will be explained through the use of the accompanying drawings and by the specification which follows.

The principal parts of this invention are illustrated in FIGURE 1, which depicts an end view of the selected embodiment of the invention and in FIGURE 2 which illustrates the positioning of the various components in a cross sectional side elevation.

Referring to FIGURE 2, the fuel line 1 is threadably fitted into a fuel duct 2 in the apparatus cylinder block 3. The duct 2 communicates with pump cylinder bores 4. The manner in which this communication is effected in this configuration is illustrated in FIGURE 1 which shows the fuel duct 2 offset from and extended beyond each such pump cylinder 4. Other means, such as positioning the duct 2 to one side of the row of cylinders 4 and using a lateral bore between the duct 2 and each cylinder may serve the communicating purpose equally as Well. The means employed is not relevant except that such means must provide uniformity with respect to depth within each cylinder 4.

Fuel may be brought from its source by gravity or other means and entered through the duct 2 and into each cylinder 4. Fuel which has been so delivered will be retained within the cylinder 4 until forced around the check valve means 5 by the pistons 6.

A critical part of this invention is the effective stroke of the pistons 6. In this connection it is to be noted that fuel will not be forced by the check valve 5 during any part of the piston travel while the lowermost extremity of the piston 6 is above the bottom of the fuel duct 2. During this part of the stroke the check valves 5 will remain closed and the fuel within the cylinder 4 which is forced ahead of the pistons 6 will course back into the duct 2 and not be forced around the check valves 5. The piston travel after the piston 6 passes the bottom of the duct 2 is the effective or pumping part of the stroke. Fuel trapped below the duct 2 is forced around the check valves 5 through the fitting 7 by the piston 6. The fuel so metered and pumped can be conveyed through a tubular type duct (not illustrated) to the engines cylinder or to any other desired point of delivery.

A second critical part of this invention is the manner of increasing and decreasing the effective piston stroke. This is accomplished by raising or lowering the camshaft 11. This is accomplished with shaft carriers 8 which are formed so as to have two bores 9 and 12 which are positioned at right angles to each other. The larger of these bores 9 is fitted over an eccentric 10 and an end of the camshaft 11 is inserted through the smaller bore 12. The camshaft 11 is extended between the two carriers 8 and positioned so that the cams 15 rest on the piston heads 17. Thus, when the arrangement is so positioned, a movement of the control arm 13 (FIGURE 1) will cause the camshaft 11 to be raised and/or lowered. The springs 14 tend to hold the piston heads 17 against the eccentric cams 15 on the camshaft 11, hence any movement of the control arm 13 which changes the position of the camshaft 11 raises or lowers the pistons 6 within the cylinders 4. Changing the position of the pistons 6 within the cylinder 4 increases or decreases the effective metering and pumping stroke of the apparatus.

The cylinder block 3 may be formed from a piece of flat stock or may be a cast part if desired. The metal used will depend upon the intended application. For example, a fuel injector system for aircraft will probably required an apparatus made with aluminum block, whereas an application on a road grader or other heavy construction machine may require the machining from a solid steel plate in order for the apparatus to withstand the expected abuse.

One apparatus cylinder 4 must be provided for each cylinder of the engine upon which this invention is to be applied.

The size of the apparatus cylinder 4 should be considered but is not critical.

The volume of liquid to be pumped is controllable by the length of the effective piston stroke as well as the diameter of the cylinder 4 and, if proper consideration is given in the design of the camshaft 11 and the eccentrics 10, minute adjustments can be given to the amounts of fuel metered by the apparatus. These adjustments are aidedby a smaller, rather than a larger cylinder 4 bore, and by larger, rather than smaller eccentrics, hence it is advisable to reduce the size of the cylinder 4 and increase the throw of the eccentrics 10 and 15 in the design of the apparatus.

As hereinabove recited, the fuel duct 2 may be formed in several different ways. The important thing in this connection is to assure that the bottom of the duct 2 or, if lateral bores are employed, the bottom of such bores, are of uniform depth Within each of the cylinder bores 4.

A smooth slidable fit between the pistons 6 and the cylinder bores 4 is required. The use of a suitable packing nut 16 as illustrated or a combination of the packing nut 16 and 0 rings will eliminate the need for a precision fit.

The exterior surfaces of the pistons 6, eccentrics 10 and the camshaft 11 and all bearing surfaces should be ground smooth and polished.

Springs 14 should be made to have sufficient tension to maintain the pistons 6 against the cams 15 of the camshaft 11. Unnecessary strength in these springs is not recommended as such strength adds nothing to the apparatus and requires the use of more power during operating periods. The check valve means 5 should be overstrength. In the majority of speed ranges of the engine the fuel will be forced back into the fuel inlet 2 rather than around the check valve 5 and if the tension of the springs in the check valves 5 is not adequate, the fuel will drool by the check valves 5 and disrupt the normal metering process.

A suitable substructure for containing the camshaft 11 is illustrated in FIGURE 1. Bracket plates 20 are positioned and secured to and form spaced apart extension of the apparatus cylinder block 3 by bolts 21 through bolt holes 22. Bearing recess bores 19 through the bracket plates 20 accommodate the shaft ends 18 of the eccentrics 10.

A control arm 13 is adapted to be fitted around the shaft ends 18 and secured in a manner whereby movement of this control arm 13 causes the eccentrics 10 to rotate. Such rotation will raise or lower the position of the camshaft 11 as hereinabove explained.

The camshaft 11 must be made operative from a flexshaft or universal type connection to insure that the up ward and downward movement can be had. Further, the apparatus must be suitably mounted onto the engine block or onto a suitable frame.

The foregoing specification clearly sets forth the invention. The selected embodiment is considered to be a suitable adaptation of the principles involved. It is to be clearly understood that there are other means of applying the basic concepts hereinabove described and that all rights are reserved when such applications fairly fall within the scope of the claims hereinafter set forth.

I claim as follows:

1. An adjustable piston actuating means for an assembly having a cylinder block, a bore in said block and a piston slidably received in said bore, said means comprising a bracket formed as spaced apart extensions of opposite sides of said cylinder block, a pair of first camshafts rotatably journalled in said opposite side extensions forming said bracket to extend therebetween transversely of the axis of said bore, an eccentric portion on each of said first camshafts, a pair of bearing blocks, each such block having a first bearing rotatably receiving one of said eccentric portions of said first camshaft and a second bearing having its axis transverse to said first camshaft and to said bore in said block, a second camshaft rotatably journalled in said second bearings of said bearing blocks, and an eccentric portion on said second camshaft in engagement with a free end of said piston outside of said bore.

2. An adjustable piston actuating means for an assembly having a cylinder block, a bore in said block and a piston slidably received in said bore; said means comprising a bracket forming an extension of said cylinder block, a first camshaft rotatably journalled in said bracket to extend therefrom transversely of the axis of said bore, an eccentric portion on said first camshaft, a bearing block having a first bearing therein rotatably receiving said eccentric portion of said first camshaft and a second bearing therein having its axis transverse to said first camshaft and to said bore in said block, a second camshaft rotatably journalled in said second bearing of said bearing block, and an eccentric portion on said second camshaft in engagement with a free end of said piston outside of said bore.

References Cited in the file of this patent UNITED STATES PATENTS 1,499,007 Edwards June 24, 1924 1,665,692 Ensign Apr. 10, 1928 2,044,064 Dake June 16, 1936 2,101,226 Sonntag Dec. 7, 1937 2,114,565 Kovach Apr. 19, 1938 2,131,779 Zwick et al. Oct. 4, 1938 2,237,347 Grannan et al. Apr. .8, 1941 2,350,678 Grimsley June 6, 1944 2 ,770,972 Gratzmuller Nov. 20, 1956 2,845,029 Gratzmuller July 29, 1958 

1. AN ADJUSTABLE PISTON ACTUATING MEANS FOR AN ASSEMBLY HAVING A CYLINDER BLOCK, A BORE IN SAID BLOCK AND A PISTON SLIDABLY RECEIVED IN SAID BORE, SAID MEANS COMPRISING A BRACKET FORMED AS SPACED APART EXTENSIONS OF OPPOSITE SIDES OF SAID CYLINDER BLOCK, A PAIR OF FIRST CAMSHAFTS ROTATABLY JOURNALLED IN SAID OPPOSITE SIDE EXTENSIONS FORMING SAID BRACKET TO EXTEND THEREBETWEEN TRANSVERSELY OF THE AXIS OF SAID BORE, AN ECCENTRIC PORTION ON EACH OF SAID FIRST CAMSHAFTS, A PAIR OF BEARING BLOCKS, EACH SUCH BLOCK HAVING A FIRST BEARING ROTATABLY RECEIVING ONE OF SAID ECCENTRIC PORTIONS OF SAID FIRST CAMSHAFT AND A SECOND BEARING HAVING ITS AXIS TRANSVERSE TO SAID FIRST CAMSHAFT AND TO SAID BORE IN SAID BLOCK, A SECOND CAMSHAFT ROTATABLY JOURNALLED IN SAID SECOND BEARINGS OF SAID BEARING BLOCKS, AND AN ECCENTRIC PORTION ON SAID SECOND CAMSHAFT IN ENGAGEMENT WITH A FREE END OF SAID PISTON OUTSIDE OF SAID BORE. 